Contents

Appearance

Onix is a Rock Snake Pokémon. Its serpentine body is made up of large boulders and little pebbles. It has a long horn atop its head and small eyes.

Special abilities

Onix can have the abilities Rock Head or Sturdy. Rock Head prevents Onix from recoiling, while Sturdy gives Onix immunity to OHKO moves . When it is burrowing underground, it can cause rumbles and earthquakes. It can dig at speeds up to 50 MPH. It has a compass in its brain that can tell Onix what direction it is facing.

In the anime

Brock received an Onix from his father, Flint, on his 10th birthday, as seen in a flashback in Having a Wailord of a Time . Onix was Brock's 1stPokémon and has consistently been his most powerful Pokemon as well.
The Crystal Onix's first and only appearance is in the anime episode The Crystal Onix. Ash and his friends first heard of it through a note they found in a bottle floating in the ocean. The note was written by a little girl named Marissa. She wanted to find the Crystal Onix to help her brother, Mateo, gain inspiration to make glass Pokémon statues. Mateo told a story of how his grandfather discovered the Crystal Onix and then was able to make extraordinary sculptures afterwards. One of those sculptures included the Crystal Onix itself.

Pokédex entries

As it grows, the stone portions of its body harden to become similar to a diamond, but colored black.

Yellow

Burrows at high speed in search of food. The tunnels it leaves are used as homes by Diglett.

Gold

It twists and squirms through the ground. The thunderous roar of its tunneling echoes a long way.

Silver

It rapidly bores through the ground at 50 mph by squirming and twisting its massive, rugged body.

Crystal

As it digs through the ground, it absorbs many hard objects. This is what makes its body so solid.

Ruby

Onix has a magnet in its brain. It acts as a compass so that this Pokémon does not lose direction while it is tunneling. As it grows older, its body becomes increasingly rounder and smoother.

Sapphire

Onix has a magnet in its brain. It acts as a compass so that this Pokémon does not lose direction while it is tunneling. As it grows older, its body becomes increasingly rounder and smoother.

Emerald

There is a magnet in its brain that prevents an Onix from losing direction while tunneling. As it grows older, its body becomes steadily rounder and smoother.

FireRed

It usually lives underground. It searches for food while boring its way through the ground at 50 miles per hour.

LeafGreen

As it grows, the stone portions of its body harden to become similar to black-colored diamonds.

Diamond

When it travels underground, it causes rumbling and tremors. It can move at 50 mph.

Pearl

It squirms through the ground using its long and rugged body. It always eats while burrowing.

Platinum

It burrows through the ground at a speed of 50 mph while feeding on large boulders.

HeartGold

It twists and squirms through the ground. The thunderous roar of its tunneling echoes a long way.

SoulSilver

It rapidly bores through the ground at 50 mph by squirming and twisting its massive, rugged body.

Black

It burrows through the ground at a speed of 50 mph while feeding on large boulders.

White

It burrows through the ground at a speed of 50 mph while feeding on large boulders.

Black 2

It burrows through the ground at a speed of 50 mph while feeding on large boulders.

White 2

It burrows through the ground at a speed of 50 mph while feeding on large boulders.

X

Burrows at high speed in search of food. The tunnels it leaves are used as homes by Diglett.

Y

It usually lives underground. It searches for food while boring its way through the ground at 50 miles per hour.

Omega Ruby

Alpha Sapphire

Etymology

Its name comes from "Onyx," a black stone that is commonly used in jewelery.

Trivia

Unshō Ishizuka, the actor best known for playing Professor Oak in the original Japanese version of the anime voices both Onix and its evolved form, Steelix in both the Japanese and English-language versions of the anime.